The sensorimotor theory of cognition holds that human cognition, along with that of other animals, is determined by sensorimotor structures rather than by uniquely human linguistic structures. The theory has been offered to explain the use of bodily terminology in nonphysical contexts, and to recognize the role of experienced embodiment in cognition. This paper defends a version of the theory which specifies that reasoning makes use of mental models constructed by means of action-planning mechanisms. Evidence is offered from cognitive psychology, the neurosciences, and work in primatology and evolutionary theory. Further scientific and philosophical advantages of the theory are discussed: the theory is more parsimonious than its rival, and it offers better accounts of intrinsic intentionality and consciousness. The paper concludes with observations concerning the role of language in thought.